Two smart phones and only one contacts list

My wife and I both have smart phones. She has a Motorola Q9c and I have an Eris (2.1v3, which has been running great with only the one or two bars issue, but that’s another post). The problem is that both phones want to use the same contacts list from Outlook. So I end up with contacts of hers that I don't want and she has some of mine that she doesn't want. Is there a way to set up different contact lists within Outlook to keep our lists separate?